1. Field of the Invention
The present invention relates to a top emission organic light emitting display and a method of manufacturing the same.
2. Description of the Related Art
An organic light emitting display having a self-emission characteristic includes a substrate on which pixels are arranged, an encapsulating substrate arranged to face the substrate, and a sealant for sealing the pixels between the substrate and the encapsulating substrate.
The organic light emitting display having the above structure is categorized as having a top emission structure or a bottom emission structure in accordance with the direction in which light is emitted from the organic light emission layers of the pixels. The top emission structure in which light is emitted in the direction of the encapsulating substrate has a higher aperture ratio than that of the bottom emission structure in which light is emitted in the direction of the substrate on which the pixels are arranged.
Since light is emitted in the direction of the encapsulating substrate in the organic light emitting display having the top emission structure, the cathode electrodes are required to be formed of a transparent electrode material such as indium tin oxide (ITO) and indium zinc oxide (IZO). However, since the transparent electrode material has a high resistivity, when the cathode electrodes are formed on the top of the display region in the form of a common electrode, a voltage difference between two locations at the common electrode occurs in accordance with the positions of the pixels corresponding to the two locations so that picture quality becomes non-uniform. That is, since a difference in brightness occurs among the pixels due to a voltage difference (voltage drop) between the positions of the pixels close to an external power source and the positions of the pixels remote from the external power source, picture quality deteriorates.